Perhaps this is just me, but the word collocation in "effects in tackling" or "effects on tackling" doesn't seem right for some reason. ie. It doesn't sound natural. Do you have a full sentence with it that we can look at ?

The correct collocation is to to have an effect ON (not 'in') something. However, I agree with Greg that the basic phrasing is wrong. Something (whatever 'its' refers to) can have an effect on a situation or a problem, but not on an action. A possible solution might be to say 'its effects on how the problem was/is tackled' or 'its effect on how people tackle(d) the problem'. Give us the full sentence if you need more help.

Effects in seems a better-suited collocation, but the complete sentence would help, cheers!

this is also my probl -.-

We need the whole sentence, or better the whole paragraph.